Tumbler lock



Dec. 24, 19290 5, g-mess 1,741,093

TUMBLER LOCK Filed Dec. 23, 1925 ficni WITNESSES Z3 INVENTOR -WE-W ATTORNEY Patented Dec. 24, 1929 UNITED STATES PATENT OFFICE STEPHEN I. BRIGGS, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO BRIGGS & STRATTON CORPORATION, OF MILWAUKEE, WISCONSIN, A CORIPORATION OF DELAWARE TUMBLER LOOK Application filed December as, 1925. Serial m. 77,297.

.This invention has for its object to provide a tumbler lock with means for securely locking in place a cap member for retaining the lock barrel in the lock-case.

Another object of the invention is to provide such locking means that will permit the cap member to freely turn with the lock barrel in the lock-case to constitute a bearing and a rotecting cover therefor.

Vith the above and other objects 111 view the invention consists in the lock as herein claimed, its parts and combinations of parts and all equivalents.

Referring to the accompanying drawings, in which like characters of reference indicate similar parts in different views,

Fig. 1 is a central sectional view of a lock constructed in accordance with this invention' Fig. 2 is a transverse sectional view thereof on the plane of line 22 of Fig. 1;

Fig. 3 is a front view with the cover removed;

Fig. 4 is a view similar to Fig. 2 showing a modification, and 1 Fig. 5 is a detail view showing the manner of compressing the locking spring for admitting the lock barrel and its cap member to the lock-case.

In these drawings, 10 indicates a lock-case which may be of any form and is here shown as constituting the head of a locking bar 11 for transmission locks for automobiles, though the invention is not confined thereto. This lock-case 10 is provided with a central shouldered bore opening from the front end, within which is rotatably mounted a lock barrel 12, preferably though not necessarily a die casting, which is provided with tumblers 13 for engaging in tumbler slots formed by grooves 14 in the walls of the bore. A cap member 15, preferably of soft steel, is tightly fitted on the front end of the lock barrel and is loosely fitted in the counterbore of the lock-case to constitute a bearing for the lock barrel and a guard for protecting its end from mutilation. The cap member has a key opening 16 registering with the key slot 17 50 of the lock barrel to receive a key 18 for withdrawing the tumblers within the lock barrel and for turning the lock barrel.

Registering grooves 19 and 20 are formed in the lock-case and cap member respectively and a locking spring ring 21 is confined in these grooves to lock the cap member against removal and to position it in the lockcase. This spring ring 21 is preferably of a shape, such as shown inFig. 2, that will cause it to pass back and forth several times across the joint between the cap member and the lock-case to effectively resist the withdrawal of the cap member from the lock-case. An alternative form of the locking spring ring, indicated as 21', is shown in Fig. 4. The form shown in Fig. 2, however, is preferred as it crosses thejoint between the parts a greater number of times and for the reason that its ends are directed outwardly against the wall of the groove in the lock-case and therefore cannot scrape against the cap member to form a resistance to the turning movements.

The arms of either form of the C-shaped locking spring ring are normally farther apart than when assembled and to facilitate the assembly a funnel-shaped guide 22 is used, as shown in Fig. 5, the guide fitting on the end of the lock-case and having a tapering bore registering with the counterbore of the lock-case so that as the lock barrel with its cap member attached and the locking spring in the groove of the cap member is entered therethrough, such locking spring is compressed to pass freely within the counterbore until it reaches the groove 19 of the lock-case, where it is permitted to spring to its locking position, as shown in Figs. 2 and 4.

Suitable locking means is controlled by the turningmovement of the lock barrel, as here shown there being a wrist-pin or cam projection 23 on the end of the lock barrel fitting in a groove in a spring-pressed lock bolt 24 slidably mounted in the lock-case and adapted to project therefrom to engage the housing for the lock-case, which is not shown, and so hold the locking bar 11 in position for locking the transmission or other mechanism controlled thereby.

It will be readily appreciated by those 100 skilled in the art that the invention is not confined to dead bolt locks of this type, but is applicable to locks of various types in which the turning of the lock barrel'is necessar to the operation of the lock.

5 shown, the look-case is rovided with a swinging dust cover 25 for c os'ing the end of the lock-case, but this forms no part'of the present invention,

In operation the cap member tightly fitting on the end of the lock barrel forms a bearing for the lock barrel and positions it in the lock-case, turning therewith when the key is inserted to remove the tumblers from the tumbler slots and prevented from removal by the locking spring. The turning of the lock barrel by means of the key causes the locking bolt 2 to be thrown into and out of its locking position.

Should any attempt he made to mutilate the lock, the brittle die cast lock barrel will be efi'ectively protected by the soft steel'cap.

The protection afiorded by the cap memberis not only-to prevent the crushing of the die cast lock barrel by blows struck thereon, but to prevent forcible withdrawal of the lock barrel by means of a powerful cam or lever havinga hook engagement therewith. That is, the tough soft steel cap not only covers the end of the lock barrel but it is positively.

locked by the spring member directly with the integral walls of the lock-case itself, compelling the shearing of the hardened steel spring at the numerous sections at which it crosses the line of parting between the lock barrel and the lock-case in. order that the lock barrel should he forcibly withdrawn and such shearing being practically impossible.

What I claim as new and desire to secure by Letters Patent is:

1. In a lock, alock-case, a lock barrel fitting therein, a cap member fixed on the lock barrel, and fitting in the lock-case to form a rotary bearing for the lock barrel, there being registering grooves in the cap member and the lock-case, and a locking ring confined in said registering grooves permitting the cap member to turn but preventing endwise displacement thereof.

2. In a look, a lock-case, a lock barrel fitting therein, a cap member tightly fitting on the lock barrel and loosely fitting in the lock-case, there being registering grooves in the cap member and the lock-case, and a locking spring confined in the registering grooves permitting the cap member to turn but preventing endwise displacement thereof.

3. In a look, .a oak-case, a lock barrel mounted therein, a cap member fitting-on the end of the lock barrel and within the lockcase, there being registering grooves in the cap member and the lock-case, and a locking ring confined in the registering grooves and crossing the joint between the cap member and the lock-case.

4;. In a lock, a lock-case, a lock barrel mounted therein, a cap member fitting on the lock barrel and within the lock-case, there being registering grooves in the cap member and the lock-case, and a locking spring normally larger in diameter than the groove of the cap member confined within the registering grooves.

5. In a lock, 2.- lock-case, a lock barrel mounted therein, a cap member fitting on the lock barrel and mounted in the lock-case, there being registering grooves in the ca member and the lock-case, and a C-shapeg locking ring confined within the registering grooves and crossing the joint between them with its ends located in the" groove of the lock-case.

6. In a lock, a lock-case having a bore with a counterbore, a lock barrel fitting within the bore, a cap member fitting on the lock barrel and contained within the counterbore, there being registering grooves in the cap member and the counterbore, and a locking spring confined within the registering grooves.

7. In a lock, a lock-case, a lock barrel therein, a protecting cap member fitting on the end of the lock-barrel and Within the lockcase, there being registering grooves in the cap member and the lock-case, and a locking ring confined in the registering grooves.

in testimony whereof, I affix my signature.

STEPHEN F. BRlGGS.

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